119. Pascal's Triangle II

Easy
Given an integer rowIndex, return the rowIndexth (0-indexed) row of the Pascal's triangle.
In Pascal's triangle, each number is the sum of the two numbers directly above it as shown:
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Example 1:
Input: rowIndex = 3
Output:
[1,3,3,1]
Example 2:
Input: rowIndex = 0
Output:
[1]
Example 3:
Input: rowIndex = 1
Output:
[1,1]
Constraints:
  • 0 <= rowIndex <= 33
Follow up: Could you optimize your algorithm to use only O(rowIndex) extra space?

解題

Runtime: 0 ms, faster than 100%
Memory Usage: 2 MB, less than 87.6%
func getRow(rowIndex int) []int {
ans := make([]int, 0)
ans = append(ans, 1)
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for i:=1; i <= rowIndex; i++ {
tmp := ans[i-1]
tmp = tmp * (rowIndex + 1 - i)
tmp = tmp /i
ans = append(ans, tmp)
}
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return ans
}

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